Head lice reproduce very quickly. The entire life cycle of a head louse from the first egg to the egg laid by an adult female, under favorable conditions, is only 16 days. And under the most unfavorable, but still allowing the reproduction of these parasites, conditions - about 30 days.
This means that already one and a half to two months after infection, a whole population of insects will live on a person’s head, and after three months they will already begin to pester the owner so much that they will cause pronounced manifestations of pediculosis.
However, despite the short life span, the way lice reproduce attracts close attention of scientists. During their fleeting life cycle, lice go through several stages of development, each of which has many features and deserves separate consideration.
The high reproduction rate of lice only adds variety and an abundance of interesting details in this process.
It is interesting
Reproduction of lice proceeds almost the same way in different species and forms of the same species.For example, the number and duration of each stage of development of lice and the duration of the developmental cycle of head, body and pubic lice are almost the same, differing only in some of the smallest details. Therefore, describing further how head lice reproduce, we will only make small notes about the features of this process in other species.
The head louse is one of two forms of a species of lice common only to humans. The second form is a product of an exclusively human civilization - a body louse, adapted to life on clothes and nutrition on the skin of a person dressing in infected things.
But the pubic louse is already a completely different species, although due to similar conditions of existence, the life cycle of pubic lice is almost identical to that of the head lice.
Life cycle of lice
Lice belong to insects with incomplete metamorphosis. This means that the developmental life cycle of head lice does not include the typical larval stage, which in other insects usually differs greatly in appearance and feeding from adults.
An adult female mates during the first day or two after the last larval molt, and after a few hours begins to lay eggs. Since the source of food (human) is always “with lice”, they do not have developmental delays due to starvation, characteristic of other parasites.
It is interesting
Lice, in principle, do not know how to starve. Each insect should eat every few hours, and if there is no food for two or three days, the louse dies. The pubic louse can fast for a maximum of 10 hours.
Lice eggs are attached to the hairs at different distances from the hair root. Each egg is dressed in a sticky case, due to which it sticks to the hair quite firmly.This design of an egg and a cap is called a nit. To the naked eye, it resembles a simple white dash on a hair, but when viewed under a microscope, it looks like a neat bag tightly wrapped around the hair.
And further: It's time to finally get those annoying nits out of your hair (the article has over 100 comments)
The larva of the first age quickly hatches from the nit. It is very similar to an adult insect, but has a very small size and an underdeveloped reproductive system. After the first saturation, such a tiny larva immediately molts and turns into a nymph.
It is interesting
In zoology, a nymph is an insect larva that differs little from adults (imago). For example, cockroaches and grasshoppers have nymphs. But in butterflies and beetles in the development cycle there is a real larva, absolutely not like an imago.
The fast cycle of lice development implies the presence of only three molts and, accordingly, three ages of nymphs. Molting is required by nymphs for the reason that the chitinous cover of their body is not elastic and cannot grow with the soft tissues of the insect. Accordingly, when such a “suit” becomes small, the nymph changes it.
After the third molt, the nymph turns into an adult insect. A female louse lays 2-4 eggs every day - up to 140 in a lifetime.
It is interesting
Body and head lice are quite different from each other in the details of the structure of the legs and some features of the shape of the body. If lice of different forms are placed in a limited volume, they can even multiply (cross), and after a few generations, the differences between them will disappear.
Reproduction of lice on the head: a process under a microscope
The reproduction of lice in humans is replete with interesting details. For example, the process of hatching a larva from an egg is interesting - an insect pierces the cover of a nit with its jaws, but cannot get out on its own. But at this time, the larva actively breathes, passing air through its digestive system and pushing it out through the anus. The air accumulating in the lower part of the nit pushes the larva out of the case, and it falls on the scalp, where it immediately begins to feed.
Different stages of development of lice are characterized by different periods of existence:
- 5-8 days nits develop
- It takes 1-3 days for a larva to turn into a first instar nymph
- 5 days the nymph of the first age develops
- The nymph of the second age develops for 8 days.
An adult louse lives from 30 to 42 days, and the recorded longevity record for these insects was 46 days. The narrowly defined life expectancy and breeding period of lice are due to the stability of the conditions in which head lice live at all stages of their development.
Female lice mate with males already in the first hours after leaving the nymph. One copulation is enough for them to fertilize all the eggs in the body. Then every day the female lays several eggs. The head louse has about 2-4 eggs per day, the pubic louse has 1-3 eggs, and the clothes louse has up to 10.
Accordingly, for your life:
- female head louse lays up to 140 eggs (usually around 80)
- female pubic louse leaves about 50 eggs
- The female body louse lays up to 300 eggs.
And further: Lice are not cockroaches, so is it worth removing them with Dichlorvos? (the article has more than 20 comments)
The egg itself in the gonads of the female is coated in a sticky secret, part of which is excreted from the oviduct before the egg. This secret forms the shell of the nit, due to which it is attached to the hair.
After the egg is laid, the secretion hardens and ensures secure attachment of the egg.
The video below clearly demonstrates how lice breed.
Interesting shots: about lice, their reproduction and the life cycle in general
In the vast majority of cases, the life cycle of a louse takes place on the surface of the head of the same person. However, in the case of close contact of people with each other or when combing, an insect can get on the head of another person and give rise to a new population here. This is how pediculosis is transmitted.
Conditions under which lice breed
Reproduction of head lice occurs in fairly limited temperature ranges. Their nits cease to develop at temperatures below 22°C and above 45°C. The optimum temperature for the rapid life cycle of the head louse is 30-31°C.
Head lice multiply as quickly as possible with a large number of them on the head, when females and males do not have to look for each other for a long time. These parasites are species-specific, meaning they cannot infect a host other than humans and some very closely related monkey species.
It is believed that lice multiply at the highest rate in places where a large number of people live together. They were a huge misfortune during wars and people living in barracks.
Features of reproduction of different types of lice
The developmental cycle of head lice is almost completely identical to that of pubic and body lice.The differences here are only in fertility (the body louse is much more prolific and, accordingly, reproduces faster, while the pubic louse lays fewer eggs) and the ability of the louse to multiply in different parts of the body. For example, the pubic louse can parasitize on the head of children, but the head louse does not even pass to the beard in men.
The features of reproduction of the head louse do not affect the methods of dealing with it. Like other parasites, the louse is poisoned by insecticide-containing shampoos, and with regular shaving of the head, the insects disappear on their own, unable to lay eggs and washed off during water procedures.
What you need to know about lice to successfully fight them
Video: potential danger of lice and methods of dealing with them
thanks for the info
Thanks for the info.
Interesting!
Thank you! Learned a lot of new and interesting things!
Everything is very interesting and even a lot of useful information) But one question sits in my head: where do they come from FROM THE BEGINNING? I would very much like to know. I've never had lice myself, so I can't imagine what it's like. My daughter's niece got lice, and decided to climb the sites and find out their origin. Everywhere they write that from another person, but where did he get them from? Don't understand. Thanks in advance.
From dirt.
Just on a clean head, lice are more likely to move on ((
Taken from dirt. Often parents do not look after their children, especially scourged parents, and this is the result.
At the moment, this is rather the trouble of prosperous families. Children at school lend each other things, change, unaware of the danger. My girls picked up this rubbish 3 times. Once at school, a boy in the next class went lousy for about a year, simply because his mother had poor eyesight and she could not process it normally. Although I could simply shave him bald, but no - I myself suffer, the child suffers, and let everyone else suffer. A nurse from the school told me about this in confidence, I was shocked, such doctors should be fired. As a result, the boy was sent for treatment at the KVD. The second time we caught it at the same school, also a boy, but a different one, he came from a sports camp from Italy. Believe me, scourging parents cannot afford this.
I again with shampoos, combs, with an iron throughout the apartment, even stroked plush toys and carpets. By the way, the hair of my beauties is below the priests, i.e. meter long.Now I’m back with irons and shampoos… We went a couple of times to the water park (by the way, it’s also not cheap) – and here’s the result… You can also pick it up in the store, measuring things that the infected person measured before you, sitting in the cinema on chairs upholstered in fabric, no one disinfects the headrests every time, at school in the locker rooms, at physical education lessons (children tumble on mats, that's enough). The list is endless. The main thing in this matter is to see and take action in time. It’s good that I’m on vacation now and I have the strength, otherwise I would hang myself ... I already thought of cutting them bald ((
Tell me, why do you need an iron?
What nonsense? All dirty.
Brad, the nicest and cleanest families suffer.
I tried on a hat in the store, as a result, the whole family became infected. The first time they got infected in Indonesia in the pool. They live quietly in the water, so water parks, swimming pools and saunas are places of increased danger.
Thank you!
I'm horrified at what kind of creatures they are.
Yeah!
Not from dirt. My daughter went to school and that's how it started. Because of these lice, I did not give her to kindergarten. All kindergartens have
From dirt lol. Where are they in kindergartens then?
Ugh, it hurts to hear about them.
I also faced this problem - my daughter got infected in the kindergarten. That's terrible.
Well, then the cockroaches are from dirt (lice are transmitted only from an infected person, and they can simply fall on you in transport when someone with a lot of lice is leaning over the person sitting).
I am horrified, I came from school - I found 100 eggs. Nightmare, I'm disgusted now.I eat food, I remember them, they make my whole head and throat covered in pimples ...
100 eggs is either 20 days for one female, or a bunch of females at once in a couple of days. Filter your surroundings.
We don’t go to kindergarten, we took a walk on the playground - and that’s it, you’re done. Now the headache is what to do and how to be ...
This is a cap. Sent the child to the village. She came for her three weeks later, got into her head and ... Mom does not see well, but she suspected that something had started. From children, from whose parents I caught as a child. They have stability. Mom told me when she was still working in the garden: their father was small, his hair was short, and it itched. They took a comb and decided to scratch it - they only counted 60 pieces, and then lost count. This is tin!
It really is just a disaster! In July of this year, the granddaughter from the kindergarten brought lice. We noticed two adults at once, and after processing and checking for a week, they calmed down, having experienced serious stress (since there are two girls and a daughter with long hair in the family). Less than 3 months later, history repeated itself. The daughter says that in the kindergarten there are children from a large Armenian family, and completely wealthy parents. From experience: there is very little to process the head, although the means are effective, it is necessary to comb out all the nits with a frequent comb. You can also warm up your hair with a flat iron for prevention.
I am very clean, my daughter always walks clean, but from any stress she gets lice. Help with advice, I'm already completely exhausted. I pickle them, choose them, but this is the second time she has appeared. Help advice.
Drip your head with dog lice drops (such as Bars) - you will forget about lice once and for all! ) Health to you and your daughter.
I couldn’t cure my own six months, but the doctors themselves in the hospital gave me advice, seeing my grief ... They don’t have the right to prescribe dog drops, but they can give a hint))
More details? How exactly to drip, how many drops, one-time drip?
Thank you. Learned a lot for myself. My son brought lice from school. Say shame to someone. What kind of doctors at school, they don’t check children ...
Doctors check by order every time after the holidays. And every month for 4-5 classes selectively. They are not psychics to know who may appear. Came from school, found a lot of nits. This is despite the fact that the female lays 4 eggs per day. Do not make me laugh. This means that the child has been infected for several days. Q: What the hell are you parents doing? Why don't you examine your children knowing about such a problem? Did you give birth to them for kindergartens and schools, or for yourself?
That's horrible! My son did not have lice in the kindergarten, now he goes to school - and in six months he has already brought 2 times ((
I went to the hospital, got infected with this infection. I have no idea what to do. Maybe someone knows the right way? Help.
The pharmacy sells remedies for pediculosis, choose the one with the comb.
Hellebore water, hot hair dryer, iron and comb to help you. We bought three different types of shampoos, sprays, which cost under a thousand. In short, there is only processing and combing out.
When I was a child, they removed these living creatures with kerosene and vinegar ... And now I tried to remove them from my daughter in the same way. Didn't see the same result. Then I comb with a comb with vinegar and rake out by hand ...
Lice is a tin ...
My daughter has not been able to remove lice for a month now. I ask: who itches at school. She admitted that she gave the girl her hairbrush at school. Here is the result.
And how many people have your daughter already infected, did you count? ))
What do lice eat?
Humans, are you kidding? ) What kind of vinegar? Lavinal with a comb, ironing through the hair, through thin strands - and they forgot. We went through this 2 times. The first time was a lot, everyone got infected, until they understood what was the matter. The whole family lavinal at a time brought out + ironing (except for the husband). Only keep lavinal 2 times more than according to the instructions, and soak until wet. It is based on oils, not chemicals, that is, it is not harmful.
What people are uneducated, I just marvel. What did you study at school for? From dirt or from nerves, no one will ever start! The louse is a living being. All living beings appear, being born from their own kind and nothing else. Are you living in the Middle Ages? If lice appear, then someone has infected you. This person got infected from another, and so on. All lice live on people, and there are already more than 7.5 billion people on Earth. It is very easy to become infected with lice, you will not even notice how it happens. Therefore, lice exist safely for as many centuries as those on whom they parasitize. As someone correctly wrote here, you can get infected anywhere - at school, at work, in transport, in a camp, etc. etc. You won’t even notice right away, which means you’ll have time to infect a bunch more people. If you or your children have had lice, then you or your children have also infected someone, it is very likely! Good luck to everyone in the fight against parasites!
Personally, our whole group and teachers are infected by a girl, her mother is a lazy, impudent, not very developed woman. The husband has obvious deviations in psycho-physical development. They don't worry about it. After complaints from their parents, they were suspended. They washed themselves, brought a certificate. My child went once last week. Babats - settlers again ... Full Marks solution (fullmarks) 450 rubles.
It is necessary then (at the next wash of the head) after washing for several weeks with lemon water to rinse. Acid destroys nits, and it is unrealistic to remove and see everything. Stay strong parents! There are more of us, we will win!
This is the third time we have taken the child out, the doctor said that it is necessary to take the whole class out. They told the teacher - the doctor came to the school, looked - no one had it! Do not go to the pool abroad? In general, lice are no longer a disease of scourges, but, on the contrary, of the rich))